The present invention relates to a method of fabricating a circuit board, and more particularly to a method of fabricating of an electric circuit board having a smooth contact surface and a minute circuit pattern.
It has been a customary practice to employ thick-film and thin-film technologies such as printing and vacuum evaporation and a transfer process for fabricating a code disk for a contact encoder by forming on an insulating substrate a minute circuit pattern having a smooth surface for contact with contactors. The circuit pattern has a minimum pattern width of 100 microns or smaller, and the code disk is required to withstand one million cycles or more of operation while in sliding contact with a contactor. The vacuum evaporation process for fabricating such a circuit board is complex and costly. In addition, conventional code disks thus formed are of a relatively short service life as the circuit pattern is made of thin film.